What condition is Gentamicin (an aminoglycoside antibiotic) typically used to treat?

From the Guidelines

Gentamycin is typically the answer to board questions about empiric antibiotic coverage for gram-negative bacteria, particularly in severe infections like sepsis, pyelonephritis, or hospital-acquired pneumonia, as well as in the treatment of infective endocarditis, especially when caused by Enterococcus spp. or Staphylococcus spp. It is an aminoglycoside antibiotic commonly used in combination with other antibiotics for synergistic effects. The typical adult dose is 5-7 mg/kg IV once daily (traditional dosing was 1.5-2 mg/kg every 8 hours) 1. Gentamycin works by binding to the 30S ribosomal subunit, inhibiting bacterial protein synthesis. Board questions often highlight its effectiveness against Pseudomonas aeruginosa, Enterobacteriaceae, and other aerobic gram-negative bacilli, while emphasizing its notable side effects of nephrotoxicity and ototoxicity. Questions frequently test knowledge about therapeutic drug monitoring, as gentamycin requires serum level monitoring to maintain efficacy while minimizing toxicity. Peak levels should be drawn 30 minutes after infusion completion, and trough levels just before the next dose, with target peak concentrations of 5-10 mcg/mL and trough levels below 2 mcg/mL to prevent toxicity 1. In the context of infective endocarditis, gentamycin is often used in combination with other antibiotics, such as ampicillin or vancomycin, and the duration of therapy can vary depending on the specific causative organism and the patient's clinical response 1. It's worth noting that gentamycin can be used in different dosing regimens, including once-daily dosing, which has been shown to be effective and may reduce the risk of nephrotoxicity 1. However, the specific dosing regimen and duration of therapy should be individualized based on the patient's clinical condition, renal function, and other factors. Some key points to consider when using gentamycin include:

• Monitoring serum levels and renal function to minimize the risk of toxicity 1
• Using gentamycin in combination with other antibiotics to enhance its effectiveness 1
• Adjusting the dosing regimen based on the patient's clinical response and renal function 1
• Being aware of the potential for gentamycin to cause nephrotoxicity and ototoxicity, and taking steps to minimize these risks 1

From the FDA Drug Label

Gentamicin Injection, USP is indicated in the treatment of serious infections caused by susceptible strains of the following microorganisms: Pseudomonas aeruginosa, Proteus species (indole-positive and indole-negative), Escherichia coli, Klebsiella-Enterobacter-Serratia species, Citrobacter species and Staphylococcus species (coagulase-positive and coagulase-negative) Clinical studies have shown gentamicin injection to be effective in bacterial neonatal sepsis; bacterial septicemia and serious bacterial infections of the central nervous system (meningitis), urinary tract, respiratory tract, gastrointestinal tract (including peritonitis), skin, bone and soft tissue (including burns)

Gentamicin is typically an answer to board questions related to the treatment of:

• Serious gram-negative infections, such as those caused by Pseudomonas aeruginosa, Escherichia coli, and Klebsiella-Enterobacter-Serratia species
• Bacterial sepsis and septicemia
• Meningitis and other central nervous system infections
• Urinary tract infections caused by susceptible organisms
• Respiratory tract infections, including those caused by Pseudomonas aeruginosa
• Gastrointestinal tract infections, including peritonitis
• Skin and soft tissue infections, including burns 2

From the Research

Board Question Topics

Gentamicin is typically an answer to board questions related to:

• Treatment of gram-negative infections, particularly those caused by Pseudomonas aeruginosa 3
• Management of severe community-acquired pneumonia (CAP) in patients admitted to the intensive care unit (ICU) 4
• Antibiotic treatment of community-acquired bloodstream infection with sepsis, especially when combined with a β-lactam antibiotic 5
• Comparison of aminoglycosides and beta-lactams in the treatment of gram-negative pneumonia 6

Key Points

• Gentamicin is an aminoglycoside antibiotic with a small therapeutic window, requiring careful dosing to minimize toxicity 7
• The optimal dosing strategy for gentamicin is still being refined, particularly in subpopulations such as obese patients, critically ill patients, and those with renal impairment 7
• Gentamicin has been shown to be safe and effective in the treatment of severe CAP, with similar outcomes to alternative Gram-negative antimicrobial regimens 4
• The addition of gentamicin to β-lactam antibiotic treatment has been associated with a decreased risk of mortality in patients with community-acquired sepsis or septic shock 5